Why were multisync crt tv sets never a thing?

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oldgamer
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Why were multisync crt tv sets never a thing?

Post by oldgamer »

Even at the time when broadcasts were transitioning from standard definition to HD, household tv sets were still not made to be multisync. Rather, digital scaling was the solution adopted. (with a few rare exceptions such as that RCA set)

I have read it was a big deal that NEC presentation monitor being multisync. But even the lowest end pc crt monitors were multisync, so why couldn't tv sets?

Is it because there was no demand for it or what?

It would solve so many problems in gaming.
Last edited by oldgamer on Thu Oct 14, 2021 9:41 pm, edited 1 time in total.
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Josh128
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Re: Why were multisync crt tv sets never a thing?

Post by Josh128 »

They were, just very uncommon in comparison to straight 15KHz sets.
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bobrocks95
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Re: Why were multisync crt tv sets never a thing?

Post by bobrocks95 »

Sounds a lot cheaper to do scaling than to put in a fully multisync chassis.

PC monitors had to support a wide array of resolutions and frame rates, so it made more sense to do multisync.
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Bassa-Bassa
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Re: Why were multisync crt tv sets never a thing?

Post by Bassa-Bassa »

What I always wondered is why 400p/480p PC monitors weren't 15khz compatible as a norm when they were transitioning from the CGA to the EGA/VGA era. Or more in particular, how come so few people complained about 200p graphics being line-doubled for 400p displays.
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Guspaz
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Re: Why were multisync crt tv sets never a thing?

Post by Guspaz »

By the time I got my first DOS computer, there was no visible scanline separation on monitors, so the concept of "line doubling" didn't come up. For 200p stuff, the pixels were just bigger on the screen.

For that matter, I never had any visible separation of scanlines on 240p consoles either, consumer televisions didn't focus tightly enough unless you paid a fortune for super high-end ones. So if anything, I'm curious where all the nostalgia for scanline filters comes from, when as far as I can tell very few people would ever have experienced classic consoles with scanline separation in the first place.
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Re: Why were multisync crt tv sets never a thing?

Post by Bassa-Bassa »

Guspaz wrote:By the time I got my first DOS computer, there was no visible scanline separation on monitors, so the concept of "line doubling" didn't come up. For 200p stuff, the pixels were just bigger on the screen.

For that matter, I never had any visible separation of scanlines on 240p consoles either, consumer televisions didn't focus tightly enough unless you paid a fortune for super high-end ones. So if anything, I'm curious where all the nostalgia for scanline filters comes from, when as far as I can tell very few people would ever have experienced classic consoles with scanline separation in the first place.
I think you're answering yourself there. As an Amiga (and arcade) user in the DOS era, my (biased) guess is that these people have realized that upscaled (blocky) pixels are a visual atrocity. Crude scanline separation is just the more popular way to display 240p, but not the only one, and you can find these days many people looking for 240p displays (or shaders) in which the scanline separation is not that prominent. And also, American people are discovering 15khz analog RGB in this century, and understanding that their composite/s-video alternatives from back in the day were far from optimal. So it's only nostalgia as such mostly for Euro people and arcade visitors.
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Re: Why were multisync crt tv sets never a thing?

Post by NJRoadfan »

Bassa-Bassa wrote:What I always wondered is why 400p/480p PC monitors weren't 15khz compatible as a norm when they were transitioning from the CGA to the EGA/VGA era. Or more in particular, how come so few people complained about 200p graphics being line-doubled for 400p displays.
Because fixed frequency monitors are cheaper.

EGA was a bi-sync standard. The 200-line CGA compatible modes all ran at 15.75khz to be compatible with the original IBM 5153 CGA monitor, while the higher resolution 640x350 mode ran at 21.8khz. To use both modes, IBM developed the fairly expensive 5154 EGA monitor. What landed up happening is just about everyone kept buying cheap CGA monitors and software writers stuck with the lower resolution modes.

When VGA came out, IBM needed a higher scan rate. Instead of going tri-sync, they setup the VGA adapter to output all modes at 31.5khz via "double strike" or other timing methods and shipped a fixed frequency monitor with the PS/2. The original VGA adapter and clones can be programmed to output 15.75khz video if needed, but this is rarely used. Nobody complained about the lack of scan lines because nobody ran Mode 13h 320x200 or Mode X software at 15khz to actually see them! There were a few transition era multiscan monitors that supported 15.75khz to around 40khz (along with TTL and analog RGB), namely the NEC Multisync and Multisync II. These monitors were expensive, but allowed someone to re-use their investment if they had a CGA machine today and upgraded to a VGA machine in the future.

Then there is the Amiga.... a special case. The machine is VERY dependent at running at 15khz. The later AGA Amigas have a feature called "mode promotion" that allows classic 200-line modes to run at 31khz like VGA cards do. The problem is software that hits the hardware directly (just about everything that isn't Workbench) doesn't support it and force the machine to 15khz. So that platform was stuck using multiscan monitors (or scan doublers) for 100% compatibility, although the vast majority of users just stuck with a good old 1084 and ignored the high-res modes.
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Re: Why were multisync crt tv sets never a thing?

Post by Dochartaigh »

oldgamer wrote:Even at the time when broadcasts were transitioning from standard definition to HD, household tv sets were still not made to be multisync. Rather, digital scaling was the solution adopted. (with a few rare exceptions such as that RCA set)

I have read it was a big deal that NEC presentation monitor being multisync. But even the lowest end pc crt monitors were multisync, so why couldn't tv sets?

Is it because there was no demand for it or what?

It would solve so many problems in gaming.
I would have to say demand. People who were going to drop at a minimum double (to quintuple+) the price of a regular SD CRT, on a high-end HD CRT were going to be totally obsessed with running at least 480p content on it, and those few rare HD broadcasts (either over the air with a special antenna, but more likely over cable with a HD-capable box which you literally had to specifically request, AND they charged you more every month for the special box, AND even more if you wanted a larger number of channels in HD). So people like that kinda expected it to look not-so-great on SD content (content which they believed to be on it's way out), so didn't care nearly as much if SD didn't look as-good on their new fancy TV because that SD content was already antiquated in their eyes so who cares about that (at least that's how I felt like the mentality of people like this was when I was working at Sears electronics back in the day).

Plus, back then, everybody's SD CRT seemed to last absolutely forever. So most people, even rich people, never even knew HD CRT's existed unless they were in the market for a new TV... I lived in a very affluent area and didn't know a SINGLE family who owned a HD CRT... and I was always a techy and would have definitely noticed and asked them a million questions about it lol. SOOO if regular people barely even new about these niche sets, that's WAY less people to put any pressure on the huge companies to make them multiformat (which would then cost the common folk more money for those added features...).




*EDIT**
Guspaz wrote:For that matter, I never had any visible separation of scanlines on 240p consoles either, consumer televisions didn't focus tightly enough unless you paid a fortune for super high-end ones. So if anything, I'm curious where all the nostalgia for scanline filters comes from, when as far as I can tell very few people would ever have experienced classic consoles with scanline separation in the first place.
My childhood vehemently disagrees with you. I grew up with a hammy-down Sony (then Mitsubishi later), and it certainly wasn't a "super high-end" Sony – it didn't even have stereo speakers and it's ONLY sole input was RF...

Image

...yet check out those scanlines on FRIGGIN RF!!!!!! (I've posted this picture before, it's stolen from a listing for the same TV I had growing up which is still up on eBay for the "retro gaming" price of $499 lol). Sony was usually always top ~5 in TV sales so it wasn't like there was a shortage of sets like this, literally tens and tens of millions of people had similar.

And before anybody counters with the lame argument of "but you didn't actually sit that close to see those scanlines" like they've tried multiple times when I posted this before... the hell we didn't. I don't know a single kid who didn't sit like 3' from the TV on the floor to better see the game on their small 14" or 20" or whatever set, not to mention how you ALWAYS play Duck Hunt better when the zapper hits the TV's glass tube lol. Heck, we didn't physically have room between the beds and dressers and everything in our rooms to sit any further back...
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Re: Why were multisync crt tv sets never a thing?

Post by gray117 »

It might seem odd to say this but TVs were sold for watching tv; there was no broadcast support for hd. So even on the higher end there was no real demand for anything other than size. Dvds wouldn't really push past the current resolutions - although they certainly increased demand for widescreens. By the time there were more uses and people with hd digital devices, crts were already on their way out. On the cost front, there was/is zero upside for the tv manufacturers to stick with crts. They couldn't be happier to make the transition to lcd/plasmas; even if older product lines could have had their lifetime increased with multisync products it made no sense for them to do so for more than a handful of users that they would charge a premium for anyway...

Plus multisync capability was just another potential point of failure. And it doesn't always work quite as well as you may imagine... Whilst monitor users were realitively used to adjusting screen geometry and choosing their refresh rate etc. with changes in resolution, a tv user wouldn't have ever accepted that same amount of fiddling.

I'm not actually sure about what the digital scaling features were you mentioned were, but I *imagine* the idea was to avoid points of failure and those user issues, and there were post processing for mpeg/dvds going on .... B&O avant tvs; the last new crts I remember seeing that were of commerical interest (and obviously at a premium) - pretty sure they had progressive scan options, though pretty sure they never went to 720/1080...
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Josh128
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Re: Why were multisync crt tv sets never a thing?

Post by Josh128 »

"Scanlines" were certainly visible on TV's larger than ~15", even back in the late 80's on shadow mask sets. That is how these games looked-- people claiming that 31KHz with faux scanlines not looking like native 15KHz are definitely mistaken. For an example, below is a collage of 3 different photos of the same Hitachi 27MM20B set. Some images are 15KHz native, some are 31KHz + faux scanlines. Anyone like to venture a guess as to which is which? :mrgreen:

Image
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Guspaz
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Re: Why were multisync crt tv sets never a thing?

Post by Guspaz »

All I can say is that none of my childhood TVs looked like that. Both the lack of visible scanline separation, and that the images were over RF and were much less clear.
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Re: Why were multisync crt tv sets never a thing?

Post by PC Engine Fan X! »

I had a 19" Tenika crt tv with rf input & it'd display the Seibu SP1 Viper Phase 1 U.S.A. game flawlessly -- had to run a S-video cable from my supergun setup and fed into a RCA composite video to rf convertor box then fed into the tv's sole input of rf.

Even the Seibu Raiden II jamma pcb played just fine on the Tenika tv as well which was impressive.

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Re: Why were multisync crt tv sets never a thing?

Post by Bassa-Bassa »

Josh128 wrote:"Scanlines" were certainly visible on TV's larger than ~15", even back in the late 80's on shadow mask sets. That is how these games looked-- people claiming that 31KHz with faux scanlines not looking like native 15KHz are definitely mistaken. For an example, below is a collage of 3 different photos of the same Hitachi 27MM20B set. Some images are 15KHz native, some are 31KHz + faux scanlines. Anyone like to venture a guess as to which is which? :mrgreen:
A bit hard with pictures like those, but anyway, never got the luck to even see in person a 27MM20B, but from my experience, large dual/tri-sync monitors at 31khz are not as sharp (by a mile) as a (good) VGA PC monitor, so the faux scanlines picture looks closer to an actual 15khz picture from a non-high end professional set. It's the picture you get from these professional monitors what I believe many people were looking for when the PVM thing exploded and what I thought Guspaz were referring to - like the result or not (I'm not a fan myself), it's hard to believe there's much actual nostalgy around this kind of low resolution display.

But I agree that scanline separation was visible even with a 14 inches monitor! I loved them on my C1084 already in the year 1988. I admit though that I didn't remember an RF image looking so well as Dochartaigh's pics, much less with the scanlines separation so clear, but I've been using exclusively RGB for more than 30 years now, so what do I know.




NJRoadfan wrote:Because fixed frequency monitors are cheaper.

EGA was a bi-sync standard. The 200-line CGA compatible modes all ran at 15.75khz to be compatible with the original IBM 5153 CGA monitor, while the higher resolution 640x350 mode ran at 21.8khz. To use both modes, IBM developed the fairly expensive 5154 EGA monitor. What landed up happening is just about everyone kept buying cheap CGA monitors and software writers stuck with the lower resolution modes.

When VGA came out, IBM needed a higher scan rate. Instead of going tri-sync, they setup the VGA adapter to output all modes at 31.5khz via "double strike" or other timing methods and shipped a fixed frequency monitor with the PS/2. The original VGA adapter and clones can be programmed to output 15.75khz video if needed, but this is rarely used. Nobody complained about the lack of scan lines because nobody ran Mode 13h 320x200 or Mode X software at 15khz to actually see them! There were a few transition era multiscan monitors that supported 15.75khz to around 40khz (along with TTL and analog RGB), namely the NEC Multisync and Multisync II. These monitors were expensive, but allowed someone to re-use their investment if they had a CGA machine today and upgraded to a VGA machine in the future.
Nice recap there, thanks. You couldn't complain if you couldn't run Mode 13 or X, I guess, but what about those who knew what a 15khz picture was through CGA, arcade or Amiga/ST monitors? That's what I meant. I remember some friends of mine with DOS VGA PCs indeed did once they saw my Amiga a couple of times. A real shame, anyway. It's like IBM not understanding what pixel art was really about and sentencing it to mass oblivion.
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Josh128
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Re: Why were multisync crt tv sets never a thing?

Post by Josh128 »

A bit hard with pictures like those, but anyway, never got the luck to even see in person a 27MM20B, but from my experience, large dual/tri-sync monitors at 31khz are not as sharp (by a mile) as a (good) VGA PC monitor, so the faux scanlines picture looks closer to an actual 15khz picture from a non-high end professional set. It's the picture you get from these professional monitors what I believe many people were looking for when the PVM thing exploded and what I thought Guspaz were referring to - like the result or not (I'm not a fan myself), it's hard to believe there's much actual nostalgy around this kind of low resolution display.
Im just saying, it doesnt matter how the pictures look or are taken, 15KHz and 31kHz + faux lines are indistinguishable from one another even in person if you adjust for brightness, whether its on a PVM, a Hitachi like this, or a tri-sync monitor.

As far as the nostalgia, I could agree with your sentiment for those who want to play on an old RF only set, but for something like this Hitachi, a PVM, or an HD CRT, with proper input signal, I honestly believe CRT is still the best type of display for playing 31KHz and lower games bar none, due to the complete and utter lack of motion blur, perfect viewing from any angle, and lack of input lag. Not even the top plasmas and OLEDs can do all those things like like the good old cathode ray tubes can.
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matt
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Re: Why were multisync crt tv sets never a thing?

Post by matt »

There are a few reasons why multisync consumer TVs are rare.

One is that with most TVs, most of the various voltages required by the tube are generated by the flyback transformer which, in turn, is driven by the horizontal deflection. This means that the flybacks output changes with different scan rates, so multisync monitors have a more complex power supply and extra circuitry to compensate for this. On HD CRTs it was probably easier to add a scaling chip.
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Josh128
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Re: Why were multisync crt tv sets never a thing?

Post by Josh128 »

Yeah about the flyback Im having a tough time trying to find a replacement for the one in these Hitachis. Got one thats got a partial parabolic horizontal collapse and makes snaps and crackles that are induced into the speakers-- only a high voltage arc can do that. So I pulled the FB with hopes of swapping with another if I run across another board with an issue I cant fix. Only thing Ive seen is HR 80452, and thats from a company in Spain that has no way to order direct as far as I can tell. I have an email in with them but havent heard back yet.

https://hrdiemen.com/reparation/flyback/model/80452

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matt
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Re: Why were multisync crt tv sets never a thing?

Post by matt »

I've found two dealers for HR flybacks. Might be useful to e-mail them, neither have that model but they might have more insight on whether it's possible to find one:

https://www.electronica-usa.com/category_FLY.html
https://www.donberg-electronics.com/cat ... raformers/
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